Various types of taut-wire protective fences are known in the patent literature and in the marketplace. Simply described, taut wire protective fences incorporate tensioned wires which are connected to sensors. These sensors provide an alarm indication of an attempt to climb or cut the fence. U.S. Pat. Nos. 3,634,638 and 3,912,893, owned by applicants, describe sensors which are paticuarly suited for taut wire fence applications and which have found wide market acceptance.
Applicant has, in the past, constructed taut wire fence installations wherein a plurality of wires are connected to a common terminal of a single sensor. Such an arrangement is also shown in later filed and published Israel Patent Application No. 60240, wherein a common member is used to attach a plurality of taut wires to a common terminal of a sensor.
In copending Israel Patent Application No. 69945, filed Oct. 10, 1983, applicant discloses and claims a taut wire fence system and sensor therefor, wherein the sensor comprises first and second taut wire connection terminals arranged for relative motion and first and second electrical contacts, each associated with a respective one of the first and second connection terminals and arranged such that a predetermined relative motion btween the first and second connection terminals produces an electrical connection between the first and second electrical contacts.
It may be appreciated that the system of Israel Patent Application No. 69945 is highly sensitive to the disturbance of two adjacent taut wires.
There exists, however, a universal concern that taut wire fence systems, even of the types described above, might be susceptible to neutralization by simultaneous clamping of the wires thereof to fixed locations on either side of a sensor.